Hello, I've been following this forum and making biodiesel glyc soap for one year now, thanks to all of you for the great resource!
I currently boil off my methanol, and in large batches it seems that I'm not getting all the methanol out. (Large batch: 10 Liters or so) I can't seem to find definitive info on what temp is required, and for how long, to make certain that the methanol is reduced to a negligible level. Here's what I've found so far-
When I boil 1 Liter of glycerin I've never had any problems, following the standard directions of 150F for 10 minutes.
For de-mething larger batches, I've found directions that say bring the temp to 260F, but elsewhere I've seen warnings that one should not raise the temp too high for fear of combustion.
Question #1: Is 260F a safe temperature for this process?
Question #2: I'm curious, since 260F is above the boiling point of water, would it dry out the glycerin and make it more solid?
#1 YES. Farmer on this forum did some substantial testing on this and it was found that a minimum temperature of 260F must be reached in order for the glycerin to be determined "non hazardous". 150F for 10 minutes is no where near sufficient for any amount in my opinion.
#2 Yes. The glycerin will be more viscous due to the evaporation of the methanol and water.
Simple schematic for a pump and heater control with a high limit
Sensor for the biodiesel/glycerin layer
I just had a thought about this. We know that methanol boils off at a lower temp than water, but the combination boils off at a higher temp. What if you dilute the byproduct with more water and then boil it off. Would the methanol boil off faster than all that additional water? Has anyone tested this?
#1 Good to know! My earlier sources only went so far as to mention 150F, some recommended 10 minutes, some did not even specify a certain amount of time, and with small batches of glyc I never noticed any negative side effects from left-over methanol.
Now that I'm doing bigger batches (and now that I know better!), I'll shoot for 260F.
#2 Also good to know, thanks
PS- below are some of those earlier information sources I was working from. Hopefully no one else has to get unnecessary methanol-headaches!
HERE is the original thread from Farmer, I had better luck finding it this morning...
This information should be a sticky, what do the rest of you think?
Simple schematic for a pump and heater control with a high limit
Sensor for the biodiesel/glycerin layer
It's always great to have new members interested in making soap from their biodiesel glycerin (BDG). Keep us posted on your success! We would love to see pictures of the soaps you make. If we can help you along the way just let us know. We hope to see you around the forum making soap for a long time to come! Unfortunately so many forum members make one or two posts and are never heard from again.
I have to agree that Farmer's thread should be added as a sticky -- it is a great source on methanol removal.
We heat our glycerin to 300*F - 350*F before we use it in our soap.
The higher temperature does also remove much of the water that may exist in the glycerin, especially if you are adding water at the end of your biodiesel process as a pre-wash.
These links are a really great introduction to BDG soaping. Most of us started with these links.
One caution you should be aware of is adding extra caustic to harden your soap. This really can be dangerous. When I and a few other members started making soap we actually burned ourselves because of the excess of caustic. You might want to spend the time and work out how much caustic you really need for your BDG. We call that a BDG Saponification (SAP) value. In many cases one size does not fit all. You can end up with caustic soap or soap that will go rancid due to an excess of superfatting.
These links will give you a great hands on experience with BDG soaps and their strengths and limitations. Check out our recipes sticky as well as they are a great guide to get you started.
If you would like a great source of information on what ingredients will work with BDG or on soap making in general please visit our website www.knicenclean.com. We have tons of recipes and lots of soap making information including MSDS information on the most popular ingredients used with BDG. We also address many of the limitations to basic BDG soap, such as hardness, lather and coloring.
If you have any questions post them here and we can try to get them answered!This message has been edited. Last edited by: Rick K,
http://www.knicenclean.com your single-most largest free BDG soaping content on the internet.
SAP Testing, Ingredient Properties, Soap Glossary and Recipes just to name a few.
Making Biodiesel Byproduct Soap Learn how to use your biodiesel byproducts to make great bar and liquid soap!!!
"Closing the loop on biodiesel production one bar at a time!"
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Isn't this forum for sharing information? I don't think there's any limit set on how much information that can be shared in a single post. PMs and e-mails are appropriate for personal discussions but shouldn't technical questions be asked in the public forum whenever possible?
Edit: What happened Rick K? You changed your message after I quoted you.
since my last post I've de-methed a batch of about 5 gallons of glyc at 260F. In the future I may shoot for a higher heat like Rick mentioned (300-350F), but for now I'm just experimenting, not selling anything from this process.
My glyc. definitely lost a lot of water at 260F, and when it cooled down it was very solid (of course, it's winter and the temp is only 58F where I left it to cool, which could contribute to that!)
When you folks have de-methed a batch of glyc, do you process it immediately into soap, or do you let it get firm and use it later? I guess it's more convenient (and energy-efficient) to process while it's still hot and liquid, but at the moment I want to get the methanol out of all my glyc, then experiment with different recipes, using a little bit at a time.
Here's an attached photo of one of my soap-batches from 6 months ago, I believe this recipe was 80% glyc, 20% coconut oil, 40g NaOH/L, 200mL Water/L. It came out really nice and firm, cleans and moisturizes well, and I've become a big fan of adding coconut oil.
biosoap-02.jpg (47 Kb, 161 downloads) Richard's biosoap
We have probably 70 gallons of demethed NAOH glycerin at the moment, been sitting for awhile. Ours is very solid at room temp. 8L of glycerin yields 64 bars and at that rate we're set for awhile unless our marketing explodes which is the goal.
260F is fine. Nice looking soap, love the molds
I am probably doing this all wrong but after 2+ years I haven't had any accidents. I use a 5 gallon bucket with a heater element near the bottom. I have a thermometer in the top as well as a fitment to vent the steam to my condenser. I have wondered about methanol remaining in my glycerol. I tend to heat it until there is nothing coming out of the condenser. When that happens I figure everything is gone. It will plateau at 150 for a while and then the temp will gradually rise to over 250. At that point, there is almost nothing coming out of the condenser. This process is usually taking about 2 hours. Is my logic flawed?
On another note I have also noticed that I eventually get a bit of distilled glycerin? bubbling up through the hose. I am calling it glycerin because it is a little milky looking and it doesn't evaporate (like methanol does) when dripped onto a hot object. I am thinking that the heat at the heater element is probably hot enough to boil some glycerin even though the temp of the entire mixture is well below glycerin's boiling point.
Of course, if I let it cook for too long (ie 2+ hours) , I get a foul burnt smelling liquid that is really nasty.
Richard have you thought about bubbling air through the glycerin to help get the methanol out.
Sinbad- thanks for mentioning the idea of bubbling the methanol out, I've seen that in other posts but haven't seen/done it in real life. I'll explore that more.
Freesoul- so, 70 gallons of NaOH Glycerine! what kind of containers do you store it in? I've done 5 gallons at a time, but when it turns semi-solid I don't have a good storage system for it.
Its stored in a 55 gallon drum and a few other containers. I need a drum heater to heat it back to liquid to make it easier to get out, have a small spade shovel that I use now and its a pain in the ass because first I have to heat it and filter it before making soap.
Until I can build a better setup I have been boiling my KOH glycerin in an open barrel with a 4500 watt 220v element in the bottom.I agitate it with lots of air from below and blow it on top with a fan.Methanol boils at 150 so adding more heat is just a waste of energy until the majority of methanol evaporates.I use a temperature controller set at 150 until things slow down then crank it up 25-50 degrees at a time until it smokes.I can not seem to get above 280 before smoking.Then I turn off the heat and let the air keep blowing until the temperature gets low enough to handle.I can not imagine more methanol could be removed from a simple system like this and would not do less. It appears impossible to get all of the methanol out.
Hello-newbie here. Not sure if anyone checks these old posts but we'll see. I've only made a few batches of bio using KOH and really high quality, water free Canola. Last soap test was 42ppm. I'm concerned about what to do with wash water and also want to start making soap ASAP.
People are talking about heating the glycerin in stills and different temperatures and also that the catalyst is still in the glycerin. I guess I'm confused. Wouldn't the catalyst be effectively gone after it's done it's job? So, freshly drained glycerin would not be good to get on the skin.
To clarify the steps...Could it be this simple?
1) Drain glycerin
2) Heat in stainless steel pot to 260F
3) Let cool and it's ready to use.
1997 Dodge Ram 2500
I am new to this forum but have a lot of Glycerin from KOK and have been reading this forum for making some soap and from what i read a large percentage of the Methanol is in the glycerin and a small percentage is in biodiesel. So I am thinking that one must be careful when heating up the glycerin as the methanol will start to evaporate and the fumes could be dangerous if not blow away with say a fan. I think you can do almost anything with the wash water, except i would not water my garden with it until i tested that. I think they are heating the glycerin in stills to recover the methanol. I would love to recover some methanol and am also wanting to make some soap ASAP.
From what i have learned your steps are about right but i have never made any soap yet. Just be careful when you are heating the glycerin as the methanol will be boiling off.
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